Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751045AbVLZKnI (ORCPT ); Mon, 26 Dec 2005 05:43:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751076AbVLZKnH (ORCPT ); Mon, 26 Dec 2005 05:43:07 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:8618 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S1751069AbVLZKnF (ORCPT ); Mon, 26 Dec 2005 05:43:05 -0500 Subject: Re: [patch 0/9] mutex subsystem, -V4 From: Arjan van de Ven To: Andrew Morton Cc: Ingo Molnar , zippel@linux-m68k.org, hch@infradead.org, alan@lxorguk.ukuu.org.uk, linux-kernel@vger.kernel.org, torvalds@osdl.org, arjanv@infradead.org, nico@cam.org, jes@trained-monkey.org, zwane@arm.linux.org.uk, oleg@tv-sign.ru, dhowells@redhat.com, bcrl@kvack.org, rostedt@goodmis.org, ak@suse.de, rmk+lkml@arm.linux.org.uk In-Reply-To: <20051226023549.f46add77.akpm@osdl.org> References: <20051222114147.GA18878@elte.hu> <20051222153014.22f07e60.akpm@osdl.org> <20051222233416.GA14182@infradead.org> <200512251708.16483.zippel@linux-m68k.org> <20051225150445.0eae9dd7.akpm@osdl.org> <20051225232222.GA11828@elte.hu> <20051226023549.f46add77.akpm@osdl.org> Content-Type: text/plain Date: Mon, 26 Dec 2005 11:42:55 +0100 Message-Id: <1135593776.2935.5.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 7bit X-Spam-Score: -2.8 (--) X-Spam-Report: SpamAssassin version 3.0.4 on pentafluge.infradead.org summary: Content analysis details: (-2.8 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -2.8 ALL_TRUSTED Did not pass through any untrusted hosts X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 593 Lines: 14 > hm. 16 CPUs hitting the same semaphore at great arrival rates. The cost > of a short spin is much less than the cost of a sleep/wakeup. The machine > was doing 100,000 - 200,000 context switches per second. interesting.. this might be a good indication that a "spin a bit first" mutex slowpath for some locks might be worth implementing... - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/